title: Ursolic acid promotes robust tolerance to cardiac allografts in mice.
abstract: Nuclear factor (NF)-κB is an important molecule in T cell activation. Our previous work has found that T cell-restricted NF-κB super-repressor (IκBαΔN-Tg) mice, expressing an inhibitor of NF-κB restricted to the T cell compartment, can permanently accept fully allogeneic cardiac grafts and secondary donor skin grafts. In this study, we explore if transient NF-κB inhibition by a small molecular inhibitor could induce permanent graft survival. Ursolic acid, a small molecular compound, dose-dependently inhibited T cell receptor (TCR)-triggered NF-κB nuclear translocation and T cell activation in vitro. In vivo, ursolic acid monotherapy prolonged significantly the survival of cardiac allograft in mice. Assisted with donor-specific transfusion (DST) on day 0, ursolic acid promoted 84·6% of first cardiac grafts to survive for more than 150 days. While the mice with long-term surviving grafts (LTS) did not reject the second donor strain hearts for more than 100 days without any treatment, they all promptly rejected the third-party strain hearts within 14 days. Interestingly, this protocol did not result in an increased proportion of CD4(+) CD25(+) forkhead box P3(+) regulatory T cells in splenocytes. That adoptive transfer experiments also did not support regulation was the main mechanism in this model. Splenocytes from LTS showed reduced alloreactivity to donor antigen. However, depletion of CD4(+) CD25(+) regulatory T cells did not alter the donor-reactivity of LTS splenocytes. These data suggest that depletion of donor-reactive T cells may play an important role in this protocol.
authors.affiliation: Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: X
authors.initials: X
authors.lastname: Huang
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: C
authors.initials: C
authors.lastname: Li
authors.forename: X
authors.initials: X
authors.lastname: Hu
authors.forename: C
authors.initials: C
authors.lastname: Xue
authors.forename: F
authors.initials: F
authors.lastname: Meng
authors.forename: P
authors.initials: P
authors.lastname: Zhou
mesh_terms: D000005:Abdomen; D019264:Adoptive Transfer; D000818:Animals; D001803:Blood Transfusion; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D004353:Drug Evaluation, Preclinical; D006082:Graft Enhancement, Immunologic; D006085:Graft Survival / Q000187:drug effects* / Q000276:immunology; D016027:Heart Transplantation / Q000276:immunology*; D007108:Immune Tolerance / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D016038:Skin Transplantation; D013047:Specific Pathogen-Free Organisms; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology; D016042:Transplantation, Heterotopic; D014184:Transplantation, Homologous / Q000276:immunology*; D014315:Triterpenes / Q000494:pharmacology / Q000627:therapeutic use*; D000097245:Ursolic Acid
chemical_list: D016328:NF-kappa B; D014315:Triterpenes; D000097245:Ursolic Acid